This invention relates to braiding machines with a drive system comprising a gear belt which meshes with drive gears to provide a synchronized drive and which operates with reduced friction. The invention further relates to braiding machines having adjustable sized beds.
Common round braiding machines have long been known to the industry. Normally, these machines are restricted in production due to the friction between the drive gears which act to move the yarn carriers about the circular bed. An effort to increase the speed and reduce the friction was attempted by U.S. Pat. No. 4,913,028 which substituted a belt and pulley drive for the drive gears. This drive, not being positive, could not maintain synchronous motion between the machine elements.
Another feature of the usual braiding machine bed is that the camway is normally cut into a metal plate. This approach is extremely expensive and produces a final size product i.e., one whose size is not adjustable. U.S. Pat. No. 2,045,515 recognized this problem and proposed the use of individual plates which are united together to form the bed. This arrangement provided adjustability but the arrangement was cumbersome and difficult to assemble.
The disclosures of the above referred to patents are incorporated with the instant disclosure.
The instant invention has for an object a braiding machine with a positive drive which operates at low friction.
Another object of the invention is a braiding machine which may operate at increased speeds.
Another object of the invention is a braiding machine in which the camway bed is formed by a plurality of identical segments united to form a unitary bed.
Another object of the invention is a braiding machine in which the camway is adjustable in size and shape.
Another object of the invention is a braiding machine in which reduced wear and friction is achieved by selective use of the component forming materials.
Another object of the invention is a braiding machine in which components are formed selectively from metal, plastic and ceramic materials for reduced friction and increased longevity.
Another object of the invention is a braiding machine in which components are coated with one of metal, ceramic and plastic materials for increased longevity and reduced friction.
Another object of the invention is a braiding machine which may be assembled to form circular or flat braided fabric.
Another object of the invention is a braiding machine which may be adjusted to vary the number of yarn carriers.
The invention is directed to a braiding machine comprised of a support table which includes a mounting surface having an upper face and a lower face. A plurality of bearing holes are formed over the mounting surface of the support table in a prescribed substantially circular pattern. A plurality of segments are secured with the upper face of the support table with adjacent segments in mutual contact. Each segment include a bearing hole which is aligned with a respective of the bearing holes formed over the mounting surface. A drive shaft extends through and is rotably mounted in each bearing hole. A first end of each shaft, which extends above the upper face, has a drive dog secured therewith. A second end of each shaft, which extends below the lower face, has a gear secured therewith. A gear belt, which is format with teeth on its inner and outer sides, is arranged in opposing drive directions about adjacent gears with the teeth of the inner and outer sides intermeshing alternately with the teeth of each of the gears. A drive motor, which drivingly engages with the gear belt, drives the shafts in positive synchronism.
Each segment includes a substantially circular segment groove formed in it upper surface. Each segment groove includes an inner and an outer wall with a pair of transfer openings formed through the outer wall at substantially opposing locations. The area of the transfer openings of adjacent segments form the points of engagement between adjacent segments forming a bed having a tracking groove forming an endless ring of circular loops.
The inner wall of each segment groove, opposite the transfer opening, includes a transfer tip which projects slightly into the camway toward the transfer opening.
A yarn carrier, which includes a foot and a base vertically spaced above the foot, is provided. The foot is positioned beneath the drive dogs and carries a tracking pawl and a follower. The follower is adapted to be engaged with the drive dogs which act to propel the yarn carrier. The tracking pawl rides in the tracking groove as the yarn carrier is moved successively about the circular loops forming the ring. A spindle mounts the base and the foot spaced from the base. The spindle also mounts the follower which engages with the drive dogs.
The braiding machine comprises, a support table having a top, a plurality of individual segments secured on the support table forming a bed of selected configuration and size on the support table. A segment groove is formed in an upper surface of each segment. Each segment groove includes an inner and an outer wall and a pair of transfer openings formed through the outer wall in substantially opposed positions. The bed carries an endless ring formed the interconnected circles formed by each segment groove. The bed is formed to a selected size and shape dependent upon the number and shape of the segments selected.
A transfer tip is formed on the inner wall of each segment opposite the transfer opening. The transfer tip extends into the tracking groove and may be formed of a material different from the material forming the remainder of the segment. The camway may be coated any one of the materials indicated in the definition. The segments may be formed of a single material, a compound of materials and may or may not be coated with a selected polymeric compound.
Each segment includes a central bore carrying a vertically disposed drive shaft. A drive dog is secured with an upper end of each drive shaft in vertically spaced relation with the associated segment. A drive is provided which rotably drives adjacent of the shafts in opposite directions.
Each drive dog comprises a circular disk having opposed notches formed in it periphery. The notches may include an insert formed of material different than the material forming the drive dog.
A yarn carrier is provided which includes a spindle mounting a foot at one end with a base vertically spaced therefrom. The base is adapted to rest on the upper surface of respective of the drive dogs while the spindle sequentially engages with respective of the drive dogs. The foot of the yarn carrier is located between the drive dogs and the segments. Rotation of the drive shafts cause the drive dogs to move the carrier about the bed formed of individual segments.
The foot of each yarn carrier carries a tracking pawl on a lower surface. The tracking pawl engages in the tracking groove and acts to stabilize the carrier during its movement about the bed. Preferably there are two of the tracking pawls on the lower surface of each foot.
The yarn carrier may be made of a selected material or the base, the foot and/or the tracking pawl may be coated with a selected material.